Economics would suggest that if an airline already operates a fleet of Airbus narrowbodies, in terms of maintenance and pilot training costs it makes sense to operate the A321 if the extra capacity is needed.

The 757 is also a little older, and this can mean increased maintenance among other things. However it has better short field ability and hot and high performance as well as better range and cargo capacity.

I think overall the A321 is cheaper to operate but the 757 has significant advantages particularly at the top end of its performance table.

A321s have commonality with the rest of the A320 series. It decreases costs significantly. It is also a lighter airplane that is a newer design. Although it has limited range, it has a lot of potential on shorter routes.

The 739 and A321 are similar planes. Continental operates the 739 side by side with the 757.

The A321 and 739 are comparable in size to the 757, but the 757 has a lot more range and payload capability. But with the extra weight of the 757, it is more expensive to operate because it isn't as efficient on shorter routes. So overall, the A321/739 and 757 can perform different tasks and are both good planes. However many airlines have opted for the 738/A320 over the A321/739 due to operating capabilities.

If you have never designed an airplane part before, let the real designers do the work!

Why would you pick the 321 instead of the 757? If you don't need the extra capability of the 757, the 321 makes good sense. BA has been putting 321s on intra-european routes instead of 757s. Those routes don't need the 757's range or takeoff performance, and thus it makes sense to do so. Plus, the 321 is in production right now (and will be for some time to come), and the 757 is not.

The 757 came out earlier, it has much better field performance than the underpowered A321. Moreover, they never updated their fuel tanks, so it's range is poor. If they gave it more fuel (and bigger engines to move that), it might be able to compete, but A321 has had soft sales, it clearly isn't that attractive. It seems like too little, too late, 757 already won over the market.

Quoting RoseFlyer (Reply 3):The A321 and 739 are comparable in size to the 757, but the 757 has a lot more range and payload capability. But with the extra weight of the 757, it is more expensive to operate because it isn't as efficient on shorter routes. So overall, the A321/739 and 757 can perform different tasks and are both good planes. However many airlines have opted for the 738/A320 over the A321/739 due to operating capabilities.

They are only almost as big as the 757. The 757 is still about 20 or so passengers larger.

Quoting FlyDreamliner (Reply 6):The 757 came out earlier, it has much better field performance than the underpowered A321. Moreover, they never updated their fuel tanks, so it's range is poor. If they gave it more fuel (and bigger engines to move that), it might be able to compete, but A321 has had soft sales, it clearly isn't that attractive. It seems like too little, too late, 757 already won over the market.

1. Different markets for the 757 and the A321
2. A321 does perfectly the job it was designed for
3. A321 is not at all "underpowered", can you please provide details on this? Referring to the better hot and high performance of the 757 is rediculous, you can't use the 757 as a benchmark here as it again was designed for a different market. The A321 is a short to medium haul 180 seater, nothing more, but nothing less, and it does this job very well, showing solid market success also relative to the 739, its most direct competitor
4. Its range is good enough and perfect for what it was designed for. Its also matching its design goals. Its not an ULH aircraft, but that market is covered by others.
5. Some carriers like US even fly the A321-200 transcon. Even though there aren't to many other carriers in the US using A321's, that should not lead you to the assumption it wasn't successful in other regions of the world.

Just flew FRA-CPH on an A321 last friday (return was the same day on an MD-87), and from a passenger point of view it's a wonderful aircraft, especially with the IAE engines, being quieter than the CFM's. Gives you a bit more of a "large aircraft" feeling than the usual 737 or A320's. And hell, the A321 can climb very well and can reach quite decent cruise altitudes fairly quickly. As most of my trips are from Frankfurt, I usually get at least around 10-15 flights per year on the A321, and I love them.

Quoting Apodino (Reply 10):I have heard numerous stories about the A321 being a bad handling plane, especially in a crosswind. It often causes some bad landings or missed approaches. I was told this by an FAA inspector.

I know a retired LH captain who during his career flew the 737, A319-A321, A343 and 744. He told me that, especially with Airbus FBW aircraft, even though they are designed to behave very similar, there are some distinct handling characteristics to each and every model. In general, he says, the longer the fuselage gets, the more "easy" it is to fly the aircraft and the more "forgiving" it behavies.

Especially on the A319 he said landing can be quite tricky if you're not used to it, as it is a fairly nervous aircraft and hard landings and very firm touchdowns happen quite often, particularly in bad weather conditions, while the A320 is easier to fly and the A321 feeling like a much bigger aircraft. His words - they might be subjective, but he has more than 35 years of flying experience. He also said the 747 and the A340, while being quite different and the A340 not being very "sporty" are "easiest" to take off and land.

Quoting FlyDreamliner (Reply 6): Moreover, they never updated their fuel tanks, so it's range is poor. If they gave it more fuel (and bigger engines to move that), it might be able to compete, but A321 has had soft sales, it clearly isn't that attractive.

Actually Airbus did make those modifications. The A321-100 was the first A321 and it really was underpowered and did lack range. Airbus added fuel tanks and increased thrust by 2-4000 lbs and increased the range by about 300nm when designing the A321-200 which entered service about three years after the initial A321-100. So the A321-200 does have the capability to fly transcon domestic flights in the United States whereas the original A321-100 did not. However there still can be some payload restrictions on longer flights with strong winds and high temperatures.

If you have never designed an airplane part before, let the real designers do the work!

The A321 has 340 some delivered and 479 ordered, not bad, but hardly the 1,000 of the 757, or well over 1,000 of the A320, 319 or various 737 variants. As for it being underpowered, here is my evidence

The 757-200 is almost a size bigger than the A321. So it is wrong to say that one is better than the other. Had Airbus built a bigger wing and strecthed the fuselage and put on some bigger engines and a new undercarriage it would have been a more similar to the 757.

But Airbus only gave the A320 a stretch, and kept the engines, wing and undercarriage.

I wonder why it was more common to do something with the wings in the early days, when Boeing used different wings on their 707, and Douglas with the DC-8. Seems like the aircraft manufacturer have hesitated to do this on later projects like the A321. Boeing is taking up that tradition with the 787.

Dream no small dream; it lacks magic. Dream large, then go make that dream real - Donald Douglas

Quoting OyKIE (Reply 14):The 757-200 is almost a size bigger than the A321.

Quoting FlyDreamliner (Reply 15):It's really not a different sized airplane. The 752 is a mere 9 feet longer than the 321, and the 321 has a wider fuselage. 757 is heavier, and more powerful, but not that much larger.

You are quite right. I used the word almost as the 757 has a greater range and Take-off performance

Dream no small dream; it lacks magic. Dream large, then go make that dream real - Donald Douglas

Quoting Mir (Reply 4):BA has been putting 321s on intra-european routes instead of 757s. Those routes don't need the 757's range or takeoff performance, and thus it makes sense to do so. Plus, the 321 is in production right now (and will be for some time to come), and the 757 is not.

the A321's work great for many carriers including BA, EI, BD, AF, etc.

I am not a fan of the 321. I think as far as a charter/IT aircraft for UK and European airlines the 757 is much more flexible in what it can do, and where it can fly.

The 321 cannot do the job of the 757, but the 757 can do the job of the 321.

in high density fit the 757 can carry 235 passengers agaisnt a maximum of 220 in the 321. The 757 can get into and out of small airports like Gibraltar with no problems, the 321 cannot (ask Monarch scheduled about that one)

Also for the charter airlines the 757 can be deployed on long haul flights from regional airports as well as being equally at home in the short haul market.

And from a purely aesthetic opinion, those engines look too small on the 321 and being on one for take off, one feel like it might not make it all the way up, especially when its fully packed with seats and luggage on an IT flight.

I love the 319/320 and the A310 but please dont get me started on that 321, I hate that aircraft with a passion.

Quoting OyKIE (Reply 14):But Airbus only gave the A320 a stretch, and kept the engines, wing and undercarriage.

However, the A321, unlike the A320 and respective shrinks, has double slotted flaps. I do wonder about the reasons why Airbus put double slotted flaps only on the A321. Why is that?

Quoting N1120A (Reply 18):The wider fuselage does nothing from an economic standpoint because it doesn't allow more seats.

But doesn't the wider fuse allow them to handle bigger cargo compared to the 757? Maybe their capacity doesn't allow much more cargo than the 757 but they could surely put wider pallets into a wider narrowbody fuse.

Quoting Orion737 (Reply 19):in high density fit the 757 can carry 235 passengers agaisnt a maximum of 220 in the 321.

Actually, the 752 is certified to 239 (753 to 295)

Quoting LTU932 (Reply 20):But doesn't the wider fuse allow them to handle bigger cargo compared to the 757? Maybe their capacity doesn't allow much more cargo than the 757 but they could surely put wider pallets into a wider narrowbody fuse.

Not particularly. Also, narrowbodies carrying pallets doesn't really make a difference given that the main restriction is weight, not volume.